The present invention relates to oil well pumping and like power conversion applications and is particularly characterized by the carrying out of such pumping with economy of capital cost and energy utilization compared to state of the art pumping and in the noisless manner with which the system of the invention operates and reduced vulnerability to breakage of the system.
Since the major underground oil well discoveries of the mid 19th century, oil well pumping has been carried out by essentially providing a piston or plunger in a tube at the end of a long rod ("sucker rod") which is stroked by an above-ground pump jack consisting of a prime mover or motor and gear reducer, pitman crank, counterweight, walking beam and mechanical linkage to reciprocate the sucker rod thus lowering and lifting a piston or plunger mechanism attached to the lower end of the rod and which in a downstroke reaches into oil in the casing defining the oil well and on the upstroke raises oil. My prior U.S. Pat. No. 4,018,547 describes utilization of certain shape memory alloy wire or said materials to replace the sucker rod and above ground equipment therefor. Such materials are capable of undergoing martensitic transformation while being cold worked and reversing the transformation on subsequent heating.
One can best describe the shape memory effect (SME) as follows. A wire, rod or piece of tubing of (SME) alloy which is deformed in the low temperature martensitic state will regain its original or memory shape upon heating. Materials exhibiting the reverse arrangement can also be made. Alloy selection can be made for specific martensitic transformation temperatures at desired levels.
Strains of up to 6 to 8% may be completely recovered in such materials. During recovery, real work can be accomplished. This recovery of memorized shape is a result of the reverse crystalline transformation of the deformed martensitic phase to the higher temperature parent phase. There are now many alloys known that exhibit the shape memory or martensitic memory effect. Some of these are nickel-titanium, nickel-aluminum, iron-platinum, copper-zinc, copper-zinc-aluminum, copper-zinc-gallium, copper-zinc-tin, copper-aluminum-nickel, copper-gold-zinc, copper-tin and gold-cadmium. These alloys are ordered and crystalographically have exhibited reversible, thermoelastic martensitic transformations.
It is an important object of the present invention to provide an improvement to my above cited invention in pumping in oil wells and other applications which in common with such invention avoids the above-ground motor and mechanical transmission and their associated capital costs, noise, friction (with attendant energy costs) and mechanical breakdown vulnerabilities and further accomplishes such while lowering oil viscosity and/or eliminating paraffin buildup in the well.
It is a further object of the invention to provide a faster stroke cycle consistent with one or more of the preceding objects.
It is a further object of the invention to reduce vulnerability of pumping system to breakage of the sucker rod within the well consistent with the preceding object.
It is a further object of the invention to provide a wide range of pump displacement (which enables an improvement in the pump stroke rate) compared with the pumps as described in my prior U.S. Pat. No. 4,018,547 consistent with one or more of the preceding objects.
It is a further object of the invention to provide a long life, reliable pumping apparatus consistent with one or more of the preceding objects.
It is a further object of the invention to provide precise control of stroke consistent with one or more of the preceding objects.